Marion County Sues Army Corps Over Plan to Drain Detroit Lake

MARION COUNTY, Ore. — The Marion County Board of Commissioners announced yesterday that the county filed a lawsuit against the US Army Corps of Engineers to pause efforts to drain Detroit Lake until the Army Corps completes the turbidity report required by federal law and allows informed public comments.

Marion County Sues US Army Corps of Engineers To Halt Draining of Detroit Lake

The US Army Corps proposed draining Detroit Lake to such a low level that it risks having insufficient water for municipal, agricultural, recreational, and environmental uses.

In addition, water will still have higher turbidity, harming water quality and costing downstream cities like Stayton and Salem millions of dollars in infrastructure repairs/upgrades.

Marion County Chair Commissioner Colm Willis highlighted that the damage to downstream water systems caused by the Army Corps’ irresponsible draining of Green Peter Lake was catastrophic and cost millions of dollars.

He said, “The damage to downstream water systems due to the Army Corps’ irresponsible draining of Green Peter Lake was not theoretical.”

Congress also required the Army Corps to evaluate lessons learned from turbidity problems caused by a similar draining of nearby Green Peter Lake, but the Army Corps is over four months past the legal deadline.

The Army Corps’ current proposal acknowledged that draining Detroit Lake could harm fish populations, but it did not fully analyze how a large-scale fish kill would affect the broader ecosystem.

In December 2025 and January 2026, Marion County submitted multiple formal letters to the Army Corps voicing strong concerns and requesting modifications to address the many foreseeable risks.

The lawsuit, filed in the United States District Court, seeks to address the Army Corps’s failure to comply with federal law and to protect local residents from potentially catastrophic consequences.